1. Field of the Invention
The present invention relates to a control interface of a vehicle in which the control interface has input controls for enabling an occupant of the vehicle to control an accessory of the vehicle.
2. Background Art
A vehicle such as an automobile has one or more control interfaces for enabling an occupant of the vehicle to control corresponding accessories of the vehicle. Each control interface includes one or more input controls (“controls”) which an occupant manipulates to control an accessory corresponding to the control interface. Each control interface may further include a display for displaying status information of an accessory corresponding to the control interface.
For example, one control interface, referred to as the instrument cluster, is behind the steering wheel for access by the driver of the vehicle. Another control interface, referred to as the center stack console, is between the driver and front passenger seats for access by both of the driver and the front passenger. Other areas of a vehicle having control interfaces include door armrests where window, mirror, and security controls are placed and overhead consoles where sunroof and interior lighting controls are placed.
A control interface such as the center stack console includes controls and a display which are associated with multiple accessories such as audio, navigation, and HVAC (heating, ventilating, and air conditioning) accessories. The surface of the control interface is divided into adjacent areas each being associated with an accessory. Each area of the control interface has controls positioned adjacent to a portion of the display. The controls are typically implemented as mechanical switches such as pushbutton switches, rockers, slide switches, and rotary switches which an operator uses to control various functions of the corresponding accessories.
Mechanical switches use a mechanical means to complete electrical contact. As a result, mechanical switches are prone to failure as their activation causes mechanical wear on their moving components and electrical contacts. Switch reliability declines and contact intermittent frequency increases over continued use. Repeated physical contact leads to deterioration of switch face legends and graphics. Mechanical switches are susceptible to contamination from external matter like dirt, food, and liquids. Ultimately, mechanical switches are expensive for automotive use. In today's automobile, mechanical switches as the controls of vehicle accessory control interfaces are responsible for some $400 or so of the automobile cost. As a result, automobiles are plagued by the problems associated with mechanical switches.
Besides their inherent physical drawbacks and cost, mechanical switches present opposition to automotive ergonomics by limiting vehicle styling and layout options. As part of a control interface for a vehicle accessory, mechanical switches are permanently fixed, numerous, and occupy significant large portions of the surface of the control interface. For example, a standard HVAC system requires controls for adjusting vent selection, blower motor speed, temperature, etc. The controls may be doubled to accommodate individual comfort control between the driver and a passenger. In a luxury class vehicle, the HVAC system may further require controls for heated mirrors, heated seats, rear passenger air flow, etc.
As vehicle accessories are augmented with additional features, the control interfaces for these accessories become increasingly complex. This is because additional accessory features create demand for more controls to accommodate operator control of the additional features. Adding mechanical switches increases the size of the control interface. If the control interface has a display associated with the accessory, then this may require expansion of the control interface to accommodate operator control of the additional features. Together the mechanical switches and the displays of a control interface consume valuable space of the surface of the control interface and increase overall cost.
Mechanical switches making up the controls of a control interface associated with an accessory must be arranged in a fashion that is comprehensive and intuitive to the operator. An excessive number of buttons or knobs clutters the control interface forcing the operator to hunt for desired switches. Sophisticated multi-function control knobs, those with switches that activate by tilting, pivoting, or swiveling, are obscure and difficult to maneuver for some operators. Furthermore, sophisticated control knobs have many intricate parts making them expensive and prone to failure.
For a vehicle accessory associated with a control interface, unique design consideration must be given to the control interface. The control interface must be accessible and convenient to operate and be visually appealing and demonstrate regard for operator safety.